Indium tin oxide target, method for manufacturing the same, transparent conductive film of indium tin oxide, and method for manufacturing transparent conductive film of indium tin oxide

ABSTRACT

Disclosed are an indium Tin Oxide (ITO) target, a method for manufacturing the same, a transparent conductive film of ITO, and a method for manufacturing the transparent conductive film of ITO. The ITO target includes at least one oxide selected from the group consisting of Sm 2 O 3  and Yb 2 O 3 , wherein an amount of the oxide is about 0.5 wt. % to about 10 wt. % based on the weight of the target.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.10-2007-0131485, filed on Dec. 14, 2007, in the Korean IntellectualProperty Office, the entire disclosure of which is incorporated hereinby reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to manufacturing a sputtering target andmanufacturing a transparent conductive film using the same, and moreparticularly, to an Indium Tin Oxide (ITO) target, a method formanufacturing the same, a transparent conductive film of ITO, and amethod for manufacturing the transparent conductive film of ITO.

2. Description of Related Art

In general, an Indium Tin Oxide (ITO) film obtained by doping tin toIndium oxide may be employed as a electrode material of a solar cell anda Flat Panel Display (FPD) such as a Liquid Crystal Display (LCD),Plasma Display Panel (PDP), Electro Luminescence Display (ELD), and thelike. In particular, demands for the ITO dramatically increase due tothe growth in the FPD market requiring the transparent electrode, and acrystalline ITO film having a relatively low resistivity may begenerally used in the FPD. The crystalline ITO film having therelatively low resistivity is obtained by performing film deposition ata high temperature or performing a predetermined heat treatment thereonafter performing the film deposition. However, the crystalline ITO filmis etched (patterned) only using a strong acid such as aqua regia (amixed solution of nitric acid and hydrochloric acid), which results in adisadvantage such that disconnection or the narrowed line width iscaused due to corrosion of gate or data lines at the time of etching theITO film using the strong acid.

In order to overcome the above disadvantage, a method for manufacturingan amorphous ITO film having superior etching characteristics has beensuggested. Specifically, manufacturing the amorphous ITO film by addinghydrogen or water to an injection gas under a low temperature atmosphereat the time of thin film deposition, and etching the amorphous ITO filmthus obtained with a weak acid may improve patterning characteristics,and prevent occurrence of the corrosion of the gate or data lines.However, this method also may incur occurrence of anomalous dischargedue to the added hydrogen or water at the time of sputtering, whichresults in disadvantages that anomalous protrusions referred to asnodules are created on an ITO target, and an impurity aggregate iscreated causing generation of a local high-resistance region on thefilm. Also, problems such as deterioration in adherence and increase incontact resistance each between the film and the substrate, debris afteretching, and the like may be created.

Also, an Indium Zinc Oxide (IZO) has been devised as a target materialfor manufacturing the amorphous film, which has superior characteristicsas an amorphous film but has a relatively poor resistivity andtransmittance and requires a relatively high cost in comparison with theITO. In addition, the IZO having characteristics such as being meltedeven in an aluminum etching agent may encounter difficulties in a casewhere a reflection electrode is formed on the transparent electrode.

SUMMARY OF THE INVENTION

An aspect of the present invention provides an Indium Tin Oxide (ITO)target and a method for manufacturing the same which may be etched witha weak acid, thereby preventing occurrence of corrosion of gate or datalines and creation of debris.

Another aspect of the present invention provides a transparentconductive film of ITO and a method for manufacturing the same which maybe excellent in etching workability even with a weak acid, and have arelatively low resistivity and high transmittance, thereby exhibitingexcellent electric and optical characteristics.

According to an aspect of the present invention, there is provided anITO target including at least one oxide selected from the groupconsisting of Sm₂O₃ and Yb₂O₃. In this instance, an amount of the oxidemay be about 0.5 wt. % to about 10 wt. % based on the weight of thetarget.

According to an aspect of the present invention, there is provided amethod for manufacturing an ITO target, the method including: mixing atleast one oxide powder selected from the group consisting of Sm₂O₃powder and Yb₂O₃ powder with In₂O₃ powder and SnO₂ powder to prepare amixed powder; mixing and wet milling the mixed powder, a dispersingagent, and a dispersion medium to prepare a slurry; drying the slurry toprepare a granular powder; molding the granular powder to form a moldedbody; and sintering the molded body. In this instance, an amount of theoxide powder may be about 0.5 to about 10 wt. % based on the weight ofthe mixed powder.

According to an aspect of the present invention, there is provided atransparent conductive film of an indium tin oxide, in which the film isdeposited on a substrate using an indium tin oxide target in a DCsputtering scheme, the indium tin oxide target including at least oneoxide selected from the group consisting of Sm₂O₃ and Yb₂O₃, and thefilm contains the oxide in an amount of about 0.5 to about 10 wt. %.

According to an aspect of the present invention, there is provided amethod for manufacturing a transparent conductive film of an ITO, themethod including: preparing an ITO target including at least one oxideselected from the group consisting of Sm₂O₃ and Yb₂O₃, an amount of theoxide being about 0.5 to about 10 wt. % based on the weight of thetarget; depositing an amorphous transparent film on a substrate usingthe target in a DC sputtering scheme; and etching the transparent filmwith a weak acid.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects of the present invention will becomeapparent and more readily appreciated from the following detaileddescription of certain exemplary embodiments of the invention, taken inconjunction with the accompanying drawings of which:

FIG. 1 is a graph illustrating x-ray diffraction results with respect toa transparent thin film formed by depositing an Indium Tin Oxide (ITO)target according to exemplary embodiments of the present invention atabout Room Temperature (RT), about 170° C., about 200° C., and about250° C., respectively;

FIG. 2 is a graph illustrating x-ray diffraction results with respect toa transparent film formed by depositing an ITO target according toexemplary embodiments of the present invention at RT, and performing aheat treatment on the deposited ITO target at about 250° C. for about 60minutes;

FIG. 3 is a graph illustrating x-ray diffraction results with respect toa transparent film formed by depositing an ITO target according toexemplary embodiments of the present invention at RT, about 170° C.,about 200° C., and about 250° C., respectively; and

FIG. 4 is a graph illustrating x-ray diffraction results with respect toa transparent film formed by depositing an ITO target according toexemplary embodiments of the present invention at RT, and performing aheat treatment on the deposited ITO target at about 250° C. for about 60minutes.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Reference will now be made in detail to exemplary embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elementsthroughout.

An Indium Tin Oxide (ITO) target according to the present inventionincludes at least one oxide selected from the group consisting of Sm₂O₃and Yb₂O₃, and thereby samarium or ytterbium is doped in the ITO, orsamarium and ytterbium are simultaneously doped therein. An amount ofthe oxide acting as a dopant is about 0.5 wt. % to about 10 wt. % basedon the weight of the target, and is preferably about 3 to about 8 wt. %.

Crystallization of the ITO target advances when the amount of the oxideis less than about 0.5 wt. % even though film deposition is performed ata low temperature, and the ITO target thus obtained hasdisadvantageously similar characteristics as in a pure ITO target.Specifically, etching on the ITO target is required to be performedusing a strong acid because of failure in etching using a weak acid,which results in creating debris after performing the etching.Crystallization of the pure ITO target without a dopant added thereinmay advance at about 140° C. According to the present invention, thereis provided an ITO target where an amorphous film is deposited even atroom temperature or at about 170° C. or less without adding hydrogen orwater therein.

Also, characteristics of a transparent conductive film (transparentelectrode) may be deteriorated due to a rapid increase in resistivitywhen the amount of oxide is about 10 wt. % or more, and thuscrystallization may be not performed even when performing heat treatmentat about 200° C.

The ITO target according to the present invention may include Sm₂O₃ andYb₂O₃, and [Sm]/([In]+[Sm]) is about 0.005 to about 0.18, and[Yb]/([In]+[Yb]) is about 0.005 to about 0. 1 8. In this instance, [Sm]denotes a number of samarium atoms per unit mass of the target, [Yb]denotes a number of ytterbium atoms per unit mass of the target, and[In] denotes a number of indium atoms per unit mass of the target. Acrystallized film is formed even at a low temperature when[Sm]/([In]+[Sm]) and [Yb]/([In]+[Yb]) are less than about 0.005 withinthe ITO target, thereby results in failure of weak acid etching. Also,resistivity of the formed film increases when the [Sm]/([In]+[Sm]) and[Yb]/([In]+[Yb]) are more than about 0.18, thereby deterioratingelectric characteristics of the conductive film.

A relative density of the ITO target according to the present inventionis about 95% or more relative to a theoretical density. A density of asputtering target is about 6.8 g/cc or more, more preferably about 7.0g/cc or more, and most preferably about from 7.1 g/cc to about 7.18g/cc. Anomalous discharge (arcing) and nodule may occur due todeterioration in electric characteristics when a relative density of thesputtering target is less than about 95%, which results in rapidreduction in efficiency of ITO target manufacturing due to frequentoccurrence of anomalous discharge.

A bulk resistance of the ITO target is about 250 μΩ·cm or less. Therearises a problem in that a Direct Current (DC) sputtering is not stablyperformed when the bulk resistance is relatively large. Thus, accordingto the present invention, samarium and ytterbium may be doped into theITO target, thereby reducing the bulk resistance.

A method for manufacturing the ITO target according to an exemplaryembodiment of the invention includes mixing at least one oxide powderselected from the group consisting of Sm₂O₃ powder and Yb₂O₃ powder withIn₂O₃ powder and SnO₂ powder to prepare a mixed powder; mixing and wetmilling the mixed powder, a dispersing agent, and a dispersion medium toprepare a slurry; drying the slurry to prepare a granular powder;molding the granular powder to form a molded body; and sintering themolded body. In this instance, an amount of the oxide powder is about0.5 to about 10 wt. % based on the weight of the mixed powder.Hereinafter, the method for manufacturing the ITO target according tothe present exemplary embodiment of the invention will be described indetail in a stepwise manner.

First, In₂O₃ powder and SnO₂ powder each having a mean particle diameterof several μm or less are compounded in a predetermined compoundingratio, for example, 8.5:1.5 or 9.5:0.5, and then the oxide powder ismixed with the resultant powder to thereby prepare the mixed powder. Inthis instance, the mixed powder may include Sm₂O₃ powder and Yb₂O₃powder, and [Sm]/([In]+[Sm]) may be about 0.005 to about 0.18, and[Yb]/([In]+[Yb]) may be about 0.005 to about 0.18. Here, [Sm] is anumber of samarium atoms per unit mass of the target, [Yb] is a numberof ytterbium atoms per unit mass of the target, and [In] is a number ofindium atoms per unit mass of the target.

Next, the slurry may be prepared by mixing and wet milling the mixedpowder, the dispersing agent, and the dispersion medium. As examples ofthe dispersing agent, a polycarboxylic acid salt may be used, however isnot limited thereto. More specifically, a polycarboxylic acid-ammoniumsalt, a polyacrylic acid-ammonium salt, a polyacrylic acid-amine salt,and the like may be used alone, or in combination of two or more thereofThe mean particle diameter of the mixed powder obtained by the wetmilling may be adjusted to be preferably 0.5 μm or less, and morepreferably 0.3 μm or less.

Next, a binder may be added in the slurry. Then, the wet milling may beadditionally performed on the slurry with the binder added therein. Inthis instance, the binder functions to maintain a molding strength ofthe molded body in the processes of the drying the slurry to prepare thegranular powder and molding the granular powder to form a molded body.As examples of the binder, polyvinyl alcohol (PVA), poly ethylene glycol(PEG), and the like are used alone or in combination two or more,however are not limited thereto. The binder may be added in an amount ofabout 0.01 wt. % to about 5 wt. % relative to a solid content of theslurry, and more preferably about 0.5 wt. % to about 3 wt. %. In thisinstance, a molding density in the process of molding the granularpowder is reduced when the amount of the binder is not in theabove-mentioned range, which may result in a reduction in a sintereddensity of a sintered body of ITO. The reduction in the sintered densitymay incur an increase in the target resistance, thereby suffering tomanufacture the sputtering target enabling the DC sputtering. Unlike theabove mentioned, the binder may be added in the process of preparing theslurry.

Next, the mixed slurry with the binder added therein is sprayed anddried to prepare the granular powder. In this instance, well-knowntechniques may be used for spraying and drying the mixed slurry, howeverthe present is not limited thereto.

Next, the molded body is manufactured by a Cold Press (CP) method and aCold Isostatic Press (CIP) method, or a combination method thereof Also,as a method for manufacturing the molded body, a slip casting method ora hot press method may be used.

The sintered body of ITO may be manufactured by sintering the moldedbody after the forming the molded body. Components composing thesintered body of ITO may exist in a uniform state through the sinteringprocess.

The sintering of the molded body may be performed at about 1,400° C. toabout 1,650° C. A sintered atmosphere at the time of sintering themolded body may be a control factor required for manufacturing thesintered body of ITO having a low bulk resistance at a lowertemperature. The sintering of the molded body may be performed in achamber having an air atmosphere, or in another chamber where an airatmosphere and an oxygen-free atmosphere are alternatively provided forthe purpose of controlling an amount of oxygen.

When the sintering process is completed, the sintered body of ITO isbonded to a copper backing plate to manufacture the ITO sputteringtarget according to the present invention.

Also, the transparent conductive film of ITO according to an exemplaryembodiment of the invention is deposited on a substrate using the ITOtarget in the DC sputtering scheme. In this instance, the ITO targetincludes at least one oxide selected from the group consisting of Sm₂O₃and Yb₂O₃, and the film contains the oxide in an amount of about 0.5 toabout 10 wt. %. Specifically, since the transparent conductive film ofITO may be manufactured using the ITO target, contents of components ofthe transparent conductive film of ITO may be the same as those of theITO target.

The transparent conductive film of ITO may have a light transmittance ofabout 80% or more in a wavelength of about 550 nm. Also, a resistivityof the transparent conductive film of ITO may be about 150 to about 500μΩ·cm.

In addition, a method for manufacturing the transparent conductive filmof ITO according to an exemplary embodiment of the invention includespreparing an indium tin oxide target including at least one oxideselected from the group consisting of Sm₂O₃ and Yb₂O₃, an amount of theoxide being about 0.5 to about 10 wt. % based on the weight of thetarget; depositing an amorphous transparent film on a substrate usingthe target in a DC sputtering scheme; and etching the transparent filmwith a weak acid. In this instance, the depositing may be performed atroom temperature to about 170° C.

The method for manufacturing the transparent conductive film of ITOaccording to the present exemplary embodiment of the invention mayinclude heat-treating and crystallizing the etched transparent film. Inthis instance, the heat-treating may be performed at about 170 to about250° C.

Hereinafter, the ITO target, the method for manufacturing the same, thetransparent conductive film of ITO, and the method for manufacturing thesame according to the present invention will be described in detail byexamples. It is to be understood, however, that these examples are forillustrative purpose only, and are not construed to limit the scope ofthe present invention.

EXAMPLES 1 TO 5

An In₂O₃ powder having a mean particle diameter of 1 μm or less and aSnO₂ powder having a mean particle diameter of 3 μm or less were mixedin a weight ratio of 9:1. Next, a Sm₂O₃ powder having a mean particlediameter of about 10 μm or less was mixed with a slurry tank to preparea mixed powder in such a manner that an amount of the Sm₂O₃ powder wasabout 0.5 wt. % in Example 1, 1.0 wt. % in Example 2, 3.0 wt. % inExample 3, 5.0 wt. % in Example 4, 7.0 wt. % in Example 5, each based ona total weight of the entire powder, respectively.

A pure water, a dispersing agent, and a binder were added in the mixedpowder, and a wet milling was performed on the resultant powder using ahard zirconia ball mill. The resultant powder was required to bepulverized for one hour for milling and mixing to prepare a slurryhaving a mean slurry particle size of 1 μm or less.

The slurry thus obtained was dried using a spray dryer to prepare agranular powder, and the granular powder was molded with a relativelyhigh pressure of about 300 MPa using a Cold Isostatic Press (CIP) toprepare a molded body Next, the molded body was sintered at a hightemperature of 1,600° C. for one hour under an air atmosphere tomanufacture a sintered body of ITO containing samarium.

A sputtering surface of the sintered body of ITO thus obtained wasgrinded using a grinder to have a diameter of 3 inches and a thicknessof 5 nm, and a backing plate was bonded to the sintered body of ITOusing an indium-based alloy to thereby manufacture a target assembly ofa sintered body. The presence of Sm₂O₃ within the target would be foundby an Electron Probe Micro Analyzer (EPMA).

Results obtained by measuring a bulk resistance of the target accordingto each Example are shown in Table 1 below.

The target according to each Example was equipped in a magnetronsputtering apparatus, and oxygen and an argon gas were injected at roomtemperature to form a transparent conductive film having a thickness ofabout 150 nm on a glass substrate.

Results obtained by measuring a light transmittance in a wavelength ofabout 550 nm with respect to the glass substrate with the transparentconductive film adhered thereon are shown in Table 1 below, in which ahigh transmittance of about 86% or more was shown. Also, a resistivityof the transparent conductive film deposited at room temperature and isshown in Table 1 below. As shown in Table 1, it was found that theresistivity of the transparent conductive film of an amorphous formed inExamples 1 to 5 was within a range of about 529 to about 1,321 μΩ·cm.

Next, the transparent conductive films in Examples 1 to 5 were subjectedto a heat-treatment at about 250° C. for 60 minutes to crystallize, andthen results obtained by measuring the resistivity thereof are shown inTable 1 below. As shown in Table 1 below, it was found that theresistivity of each of the transparent conductive films in whichcrystallization was achieved through a heat-treatment of hightemperature was within a range of about 176 to about 333 μΩ·cm.

FIG. 1 is a graph illustrating x-ray diffraction results with respect toa transparent thin film formed by depositing the ITO target according toExamples 3 to 5 at Room Temperature (RT), about 170° C., 200° C., and250° C., respectively. (a), (b), and (c) of FIG. 1 may correspond toExamples 3, 4, and 5, respectively.

As shown in FIG. 1, it was found that a peak was observed at about 200°C. in Examples 3 and 4, and a peak was observed at about 250° C. inExample 5 to achieve crystallization. The transparent conductive film ofthe amorphous was formed even when the ITO target ((a) and (b) ofFIG. 1) respectively containing samarium in an amount of about 3 wt. %and 5 wt. % was deposited at a high temperature of about 170° C. Also,the transparent conductive film of the amorphous was formed even whenthe ITO target ((c) of FIG. 1) containing samarium in an amount of about7 wt. % was deposited at a high temperature of about 200° C.

FIG. 2 is a graph illustrating x-ray diffraction results with respect toa transparent film formed by depositing the ITO target in Examples 1 to5 at RT, and performing a heat-treatment on the deposited ITO target atabout 250° C. for about 60 minutes. Only a peak originated from indiumwas observed in all thin films of Examples 1 to 5, and crystallizationof each of the thin films was achieved. Specifically, the transparentconductive film deposited at room temperature to about 170° C. was in anamorphous state, however the crystallization of the transparentconductive film was achieved after performing the heat-treatment at ahigh temperature of about 250° C. as shown in FIGS. 1 and 2.

Also, as shown in Table 1 below, a temperature required forcrystallizing the film increased along with an increase in the amount ofthe samarium, and the transparent conductive film of the amorphous wasformed even when the ITO target containing samarium in an amount ofabout 3 wt. % or more was deposited at a temperature less than about200° C. Also, the transparent conductive film of the amorphous wasformed when the ITO target each containing the samarium in an amount ofabout 0.5 wt. % and 1 wt. % was deposited at a temperature less thanabout 170° C.

EXAMPLES 6 TO 10

An In₂O₃ powder having a mean particle diameter of 1 μm or less and aSnO₂ powder having a mean particle diameter of 3 μm or less werecompound in a weight ratio of 9:1. Next, a Yb₂O₃ powder having a meanparticle diameter of about 10 μm or less was mixed with a slurry tank toprepare a mixed powder in such a manner that an amount of the Sm₂O₃powder was about 0.5 wt. % in Example 6, 1.0 wt. % in Example 7, 3.0 wt.% in Example 8, 5.0 wt. % in Example 9, 7.0 wt. % in Example 10 eachbased on a total weight of the entire powder, respectively.

A pure water, a dispersing agent, and a binder were added in the mixedpowder, and a wet milling was performed on the resultant powder using ahard zirconia ball mill. The resultant powder was required to bepulverized for one hour for milling and mixing to prepare a slurryhaving a mean slurry particle size of 1 μm or less.

The slurry thus obtained was dried using a spray dryer to prepare agranular powder, and the granular powder was molded with a relativelyhigh pressure of about 300 MPa using a Cold Isostatic Press (CIP) toprepare a molded body Next, the molded body was sintered at a hightemperature of 1,600° C. for one hour under an air atmosphere tomanufacture a sintered body of ITO containing ytterbium.

A sputtering surface of the sintered body of ITO thus obtained wasgrinded using a grinder to have a diameter of 3 inches and a thicknessof 5 nm, and a backing plate was bonded to the sintered body of ITOusing an indium-based alloy to thereby manufacture a target assembly ofa sintered body. The presence of Yb₂O₃ within the target would be foundby an Electron Probe Micro Analyzer (EPMA).

Results obtained by measuring a bulk resistance of the target accordingto each Example are shown in Table 1 below.

The target according to each Example was equipped in a magnetronsputtering apparatus, and an oxygen and an argon gas were injected atroom temperature to form a transparent conductive film having athickness of about 150 nm on a glass substrate.

Results obtained by measuring a light transmittance in a wavelength ofabout 550 nm with respect to the glass substrate with the transparentconductive film adhered thereon are shown in Table 1 below, in which ahigh transmittance of about 86% or more was shown. Also, a resistivityof the transparent conductive film deposited at room temperature isshown in Table 1 below. As shown in Table 1, it was found that theresistivity of the transparent conductive film of an amorphous formed inExamples 6 to 10 was within a range of about 579 to about 831 μΩ·cm.

Next, the transparent conductive films in Examples 6 to 10 weresubjected to a heat-treatment at about 250° C. for 60 minutes tocrystallize, and then results obtained by measuring the resistivitythereof are shown in Table 1 below. As shown in Table 1 below, it wasfound that the resistivity of each of the transparent conductive filmsin which crystallization was achieved through a heat-treatment of hightemperature was within a range of about 188 to about 474 μΩ·cm.

FIG. 3 is a graph illustrating x-ray diffraction results with respect toa transparent film formed by depositing the ITO target according toExamples 6, 8, and 10 at RT, about 170° C., about 200° C., and about250° C., respectively. (a), (b), and (c) of FIG. 3 may correspond toExamples 6, 8, and 10, respectively.

As shown in FIG. 3, it was found that a peak was observed at about 170°C. in Example 6, a peak was observed at about 200° C. in Example 8, anda peak was observed at about 200° C. to achieve crystallization. Thetransparent conductive film of the amorphous was formed even when theITO target ((a) and (b) of FIG. 3) respective containing ytterbium in anamount of about 0.5 wt. % and 3.0 wt. % was deposited at a temperatureless than about 170° C. Also, the transparent conductive film of theamorphous was formed even when the ITO target ((c) of FIG. 3) containingytterbium in an amount of about 7.0 wt. % was deposited at a hightemperature of about 170° C.

FIG. 4 is a graph illustrating x-ray diffraction results with respect toa transparent film formed by depositing the ITO target in Examples 6 to10 at RT, and performing a heat treatment on the deposited ITO target atabout 250° C. for about 60 minutes.

Only a peak originated from indium was observed in all thin films ofExamples 6 to 10, and crystallization of each of the thin films wasachieved. Specifically, the transparent conductive film deposited atroom temperature to about 170° C. was in an amorphous state, however thecrystallization of the transparent conductive film was achieved afterperforming the heat-treatment at a high temperature of about 250° C. asshown in FIGS. 3 and 4.

COMPARATIVE EXAMPLE 1

An In₂O₃ powder having a mean particle diameter of 1 μm or less and aSnO₂ powder having a mean particle diameter of 3 μm or less werecompound in a weight ratio of 9:1 to thereby prepare a mixed powder.Pure water, a dispersing agent, and a binder were added in the mixedpowder, and a wet milling, drying, molding, and sintering processes wereperformed in the same manner as that in Examples 1 to 10 to therebyprepare a pure sintered body of ITO without samarium or ytterbium addedtherein. The sintered body of ITO was processed in the same manner asthat in Examples 1 to 10 to manufacture a target, and results obtainedby measuring a bulk resistance and density of the target are shown inTable 1 below.

The target according to Comparative Example 1 was equipped in amagnetron sputtering apparatus, and oxygen and an argon gas wereinjected at room temperature to form a transparent conductive filmhaving a thickness of about 150 nm on a glass substrate.

Results obtained by measuring a light transmittance in a wavelength ofabout 550 nm with respect to the glass substrate with the transparentconductive film adhered thereon are shown in Table 1 below.

Next, the transparent conductive film according to Comparative Example 1was subjected to a heat-treatment at about 250° C. for 60 minutes, andresults obtained by measuring a resistivity of the transparentconductive film are shown in Table 1 below.

TABLE 1 Light Kind transmittance Resistivity Resistivity and of film offilm of film content Bulk Density deposited at deposited subjectedTemperature of resistance of high at high to heat- for dopant of targettarget temperature temperature treatment crystallizing (wt. %) (μΩ · cm)(g/cc) (%) (μΩ · cm) at 250° C. film (° C.) Example 1 Sm, 0.5 160 7.1086 529 176 170 Example 2 Sm, 1.0 170 1.11 86 626 201 170 Example 3 Sm,3.0 190 7.136 87 801 225 200 Example 4 Sm, 5.0 220 7.153 88 1107 263 200Example 5 Sm, 7.0 250 7.182 89 1321 333 250 Example 6 Yb, 0.5 160 7.1086 579 188 170 Example 7 Yb, 1.0 170 7.11 86 586 211 170 Example 8 Yb,3.0 190 7.136 88 606 278 170 Example 9 Yb, 5.0 220 7.153 90 712 395 200Example 10 Yb, 7.0 250 7.182 91 831 474 200 Comparative Nothing 350 7.1486 430 182 140 Example 1

As described above, it was found that crystallization of the thin filmwas achieved even when the deposition temperature of the ITO target isrelatively low in a case of the ITO target without samarium or ytterbiumadded therein, whereas the transparent conductive film of the amorphouswas deposited and formed at a temperature less than about 170° C. oreven at about 200° C. according to the contents of the components in acase of the ITO target with samarium and ytterbium added therein. Thetransparent conductive film of the amorphous may be etched with a weakacid, thereby exhibiting superior etching workability compared to theexisting target, and preventing creation of debris due to the etchingprocess. Also, the transparent conductive film of crystalline havingsuperior electric characteristics may be manufactured when beingsubjected to a heat-treatment at about 170 to about 250° C.

As described above according to the present invention, the ITO targethas a relatively low bulk resistance, thereby performing a stable DCsputtering. Also, a density of the target is relatively high, therebypreventing occurrence of anomalous discharge and nodule at the time ofsputtering.

The transparent conductive film of the amorphous formed on the substrateusing the ITO target according to the present invention is etched with aweak acid, thereby preventing occurrence of corrosion of gate or datalines and creation of debris, which may be inevitably incurred by astrong acid in the existing target. Also, the transparent conductivefilm of the amorphous has a low resistivity and superior lighttransmittance.

The transparent conductive film of ITO according to the presentinvention crystallizes the thin film of the amorphous by means of aheat-treatment, thereby exhibiting superior etching workability andoptical characteristics.

Although a few exemplary embodiments of the present invention have beenshown and described, the present invention is not limited to thedescribed exemplary embodiments. Instead, it would be appreciated bythose skilled in the art that changes may be made to these exemplaryembodiments without departing from the principles and spirit of theinvention, the scope of which is defined by the claims and theirequivalents.

What is claimed is:
 1. An indium tin oxide target including Sm₂O₃ andYb₂O₃, wherein an amount of the Sm₂O₃ and Yb₂O₃is about 0.5 wt. % toabout 10 wt. % based on the weight of the target, wherein[Sm]/([In]+[Sm]) is about 0.005 to about 0.18, and [Yb]/([In]+[Yb]) isabout 0.005 to about 0.18, and wherein [Sm] is a number of samariumatoms per unit mass of the target, [Yb] is a number of ytterbium atomsper unit mass of the target, and [In] is a number of indium atoms perunit mass of the target.
 2. The indium tin oxide target of claim 1,wherein a Direct Current (DC) sputtering is applied to the indium tinoxide target.
 3. The indium tin oxide target of claim 1, wherein adensity of the indium tin oxide target is about 7.10 g/cc to about 7.18g/cc.
 4. The indium tin oxide target of claim 1, wherein a relativedensity of the indium tin oxide target is about 95% or more.
 5. Theindium tin oxide target of claim 1, wherein a bulk resistance of theindium tin oxide target is about 250 μΩ·cm or less.